The present invention generally relates to idler rollers for conveyors and, more particularly, to bearing assemblies for such idler rollers.
A belt conveyor is conventionally supported between its ends by a plurality of carriers. Each carrier typically includes a frame extending transversely to the conveyor belt and journals generally three idler rolls in an end-to-end relationship. Generally, the intermediate idler roll is disposed in a horizontal position while the outer two idler rolls are disposed at an upwardly inclined angled relationship to a horizontal plane to give the conveyor belt a trough-like shape for the purpose of keeping a load centered on the conveyor belt.
The idler rolls typically have bearing assemblies, which are interposed between a rotating roller shell and a stationary shaft. While the bearing assemblies are commonly ball bearings, it is desirable for the bearing assemblies to be tapered roller bearings because they can provide twice the minimum life of ordinary ball bearings. The tapered roller bearings, however, require precise axial clearance settings. The tapered roller bearings have been secured with threaded assemblies and/or snap rings with compensating washers to account for manufacturing variations. Thus the idler rolls with tapered roller bearings are relatively complex to produce and are relatively expensive.
It is generally known to press various bearings onto various shafts. This is a rather simple and low-cost approach. The long shaft lengths of idler rolls, however, have made press fitting tapered roller bearings directly onto the metal shaft impractical because of the precise axial clearance seating required versus shaft flexibility and compressibility.
Accordingly, there is a need in the art for an idler bearing having tapered roller bearings that have precise and consistent end-play settings, is relatively easy to produce, and is affordably priced. There is also a need in the art for a method of producing such idler bearings and a device for automatically producing a high volume of such idler rolls.